Netflix is one of the companies who have moved away successfully and entirely to cloud and in the process they leveraged and developed Microservices development best practices, tools (Netflix OSS), and guidelines.
https://martinfowler.com/articles/microservices.html
Mastering Chaos - A Netflix Guide to Microservices [YouTube]
When To Use Microservices (And When Not To!) - Sam Newman & Martin Fowler [YouTube]
Methodology to build scalable SaaS apps. Drafted by developers at Heroku and first presented in 2011.
Website: https://12factor.net
A good guide with visuals and short descriptions: https://www.redhat.com/architect/12-factor-app
In Spring Boot: https://www.baeldung.com/spring-boot-12-factor
Software in the 90s used to be designed for distribution on CDs, it was in stark contrast to cloud-native apps of today.